From: Richard Yao <ryao@gentoo.org>
To: Andy Lutomirski <luto@amacapital.net>
Cc: Dominique Martinet <dominique.martinet@cea.fr>,
Will Deacon <will.deacon@arm.com>,
V9FS Developers <v9fs-developer@lists.sourceforge.net>,
Eric Van Hensbergen <ericvh@gmail.com>,
Ron Minnich <rminnich@sandia.gov>,
Latchesar Ionkov <lucho@ionkov.net>,
Rusty Russell <rusty@rustcorp.com.au>,
"linux-mm@kvack.org" <linux-mm@kvack.org>
Subject: Re: [V9fs-developer] finit_module broken on 9p because kernel_read doesn't work?
Date: Sat, 08 Feb 2014 19:34:59 -0500 [thread overview]
Message-ID: <52F6CD33.80607@gentoo.org> (raw)
In-Reply-To: <CALCETrUNgNyMd1CqdmePKxw1+eA-ixKx0=3MvL8Prw7CNOPA9g@mail.gmail.com>
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On 02/08/2014 02:54 PM, Andy Lutomirski wrote:
> On Sat, Feb 8, 2014 at 11:27 AM, Richard Yao <ryao@gentoo.org> wrote:
>> On 02/08/2014 02:20 PM, Andy Lutomirski wrote:
>>> Are we looking at the same patch?
>>>
>>> + if (is_vmalloc_or_module_addr(data))
>>> + pages[index++] = vmalloc_to_page(data);
>>>
>>> if (is_vmalloc_or_module_addr(data) && !is_vmalloc_addr(data)), the
>>> vmalloc_to_page(data) sounds unhealthy.
>>>
>>> --Andy
>>>
>>
>> Mainline loads all Linux kernel modules into virtual memory. No
>> architecture is known to me where this is not the case.
>>
>
> Hmm. I stand corrected. vmalloc_to_page is safe on module addresses.
>
> --Andy
>
I also stand corrected. After you poked me on this, I sent this patch
with a second patch to export is_vmalloc_or_module_addr() to Linus
Torvalds, who wrote is_vmalloc_or_module_addr(). He provided a very
concise explanation why is_vmalloc_addr() is not only safe, but preferable:
https://lkml.org/lkml/2014/2/8/272
I have resubmitted it with that change. I expect it to be merged soon.
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prev parent reply other threads:[~2014-02-09 0:35 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CALCETrWu6wvb4M7UwOdqxNUfSmKV2eZ96qMufAQPF7cJD1oz2w@mail.gmail.com>
[not found] ` <20140207195555.GA18916@nautica>
[not found] ` <CALCETrWZvz85hxPGYhgHoF4yp06QkP4SxWQBSxFqmTyCqhE3LA@mail.gmail.com>
[not found] ` <52F66641.4040405@gentoo.org>
2014-02-08 17:55 ` Andy Lutomirski
2014-02-08 18:05 ` Richard Yao
2014-02-08 19:13 ` Andy Lutomirski
2014-02-08 19:16 ` Richard Yao
2014-02-08 19:20 ` Andy Lutomirski
2014-02-08 19:27 ` Richard Yao
2014-02-08 19:54 ` Andy Lutomirski
2014-02-09 0:34 ` Richard Yao [this message]
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